Non-symmetric, partially fluorinated lubricant additives

ABSTRACT

Novel non-symmetric, partially fluorinated compositions and method of manufacture which are useful as lubricants or as additives to lubricant formulations involving the molecular structure:  
     R 1f —F′—R 2 —F″—R 3h    
     where R 1f  represents a wholly or partially fluorinated organic residue end group, F′ and F″ represent functional linkages which may be alike or different, R 2  represents the backbone and R 3h  represents a non-fluorinated organic residue end group. Such compositions are produced by reacting a mixture of alcohols, mercaptans or amines containing at least one partially fluorinated compound and at least one non-fluorinated compound in the mixture, thus producing the R 1f  and the R 3h  residues, with a difunctional organic compound (e.g., diacid, dinitrile, disulfonyl halide, diisocyanate, diisothiocyanate, diphosphoryl halide or dithiophosphoryl halide).

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Applicants claim the benefit of Provisional Application60/083,115 filed Apr. 27, 1998 and Non-Provisional Application09/299,251 filed Apr. 26, 1999 now allowed.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] “Not Applicable”

BACKGROUND OF THE INVENTION

[0003] 1. Field of the Invention

[0004] This invention relates to lubricants. In particular, it describesnon-symmetric, partially fluorinated lubricants and additives, which aresoluble in lubricating oils and impart anti-wear and friction-reducingbenefits to lubricant formulations.

[0005] 2. Description of the Prior Art

[0006] Two of the most important functions of a lubricant are to reducefriction and to reduce wear on moving parts. Full-film lubrication,where moving parts are always separated by a film of lubricant such thatthe parts never make contact, is an ideal that cannot always be achievedin practice. Design constraints, together with high load, slow speed,lubricant starvation, or low viscosity of the lubricant, may precludefull-film lubrication and increase the severity of contact. Theseconditions are often unavoidable during normal operation of machinery,and particularly severe during startup and shutdown.

[0007] In cases where full-film lubrication cannot be ensured at alltimes, anti-wear agents and friction modifiers are usually employed tomodify the surfaces to be lubricated. Such anti-wear agents modify thesesurfaces through adsorption or chemical reaction to form a new surfacethat can reduce friction and resist wear. Many kinds of anti-wear agentsare known. Some of the most widely used and relied upon are the zincdialkyldithiophosphates (ZDDPs), which find application in manydifferent types of lubricants. Although these compounds have been usedfor many years in passenger car motor oil, their use is currentlyrestricted (0.1% P vs. 0.12% allowed in the previous GF-1 specification)because the phosphorus from ZDDP poisons catalytic converters, leadingto increased emissions. It is anticipated that the future use of ZDDPmay be reduced even more than the current level. Anti-wear agents, whichcan be used in place of ZDDP or in addition to it, are therefore ofgreat interest.

[0008] Use of fluorinated and partly-fluorinated materials, aslubricants are known. One limitation of the fluorinated andpartly-fluorinated materials previously known is their very lowsolubility in conventional lubricant base fluids such as natural andsynthetic hydrocarbons and esters. Although solid additives may be usedin lubricants, they pose several problems. For example, it is known thatsolid polytetrafluoroethylene (PTFE) can be dispersed in lubricantfluids to reduce friction and wear. However, effectiveness of such adispersed lubricant depends on maintaining the solid PTFE particles instable dispersion. Achieving an indefinitely stable dispersion is achallenge, particularly in a formulated lubricant, which may containdetergents, dispersants, or surfactants that may destabilize the PTFEdispersion. Particles of a dispersed solid may flocculate over time inuse. Such flocculated particle may then plug or restrict flow of thelubricant in the equipment and result in lubricant starvation incritical locations. The use of soluble additives instead of dispersedsolid additives eliminates this problem.

[0009] Unfortunately, in the case of PTFE, there is no equivalentmaterial that is soluble in common mineral oil base fluid. Otherfluorinated materials have been developed as lubricants, including someliquid highly fluorinated materials such as perfluoropolyethers, buteven these liquid highly-fluorinated materials are insoluble in commonmineral oil base fluids.

[0010] Finally, highly fluorinated materials are significantly moreexpensive than common lubricant base fluids, making it impractical touse highly fluorinated materials themselves as base fluids except incertain specialized uses where lower cost base fluids are notacceptable.

[0011] In the prior art, the terms “partly-fluorinated” and “partiallyfluorinated” can be confusing since they may be used interchangeably, oreither one or both terms may used to refer generically to many differenttypes of organic compounds having some but not all of the hydrogenreplaced by fluorine substituents. Thus the terms as used in the priorart do not necessarily adequately describe the structure of the moleculein regard to placement of the fluorine substituents.

[0012] As used herein the term partly-fluorinated means that both endgroups of a molecule are fluorinated to some extent. Partly-fluorinatedmaterials, particularly esters and ethers, have been disclosed aslubricants for magnetic media, for example, Japanese Patent 259482,Japanese Patent 08259501, and U.S. Pat. Nos. 5,578,387; 5,391,814 and5,510,513.

[0013] Japanese Patent 01122026 teaches use of fluorine containingdibasic acid esters derived from diacids up to C₈ as lubricants formagnetic media. This publication, as does PCT publication, US/92/08331,teaches that the acid structure from which the diester is formed mayhave double bonds present. The molecular structures taught by each ofthese publications may also have fluorine atoms present in each of theend group.

[0014] Partly-fluorinated adipic acid diesters,R_(f)(CH₂)_(x)O₂C(CH₂)₄CO₂(CH₂)_(x)R_(f), have been disclosed aslubricating coatings by Russian patent SU 449925. Bowers et al (Lubr.Eng., July-August, 1956, pages 245-253) studied the boundary lubricatingproperties of several similar esters. The compounds disclosed in thispublication have fluorine present in each of the diester groups that isthe fluorination is symmetric. These partly-fluorinated esters have verylow solubility in conventional lubricant base fluids and are therefore,of limited utility as additives in such base fluids.

[0015] Japanese Patent 2604186 discloses 1,2,3,4-butane-tetracarboxylicacid tetraesters with partly-fluorinated alcohols, but since all fourester groups are derived from fluorinated alcohols, these esters, too,are symmetric. Other examples of the teaching of symmetricallyfluorinated molecular structures include U.S. Pat. Nos. 4,203,856;5,066,856 and 4,039,301 and in JP08258482 and JP08259501.

[0016] Fluorine-containing tri-carbonyl compounds, including someesters, are disclosed as lubricant additives in Japanese patent JP07242584, and partial fluoroesters of polycarboxylic acids, in which theacid functional groups are not completely esterified was taught in U.S.Pat. No. 3,124,533.

BRIEF SUMMARY OF THE INVENTION

[0017] In view of the above description of the prior art, it is anobject of the present invention to provide a fluorinated lubricantadditive which can serve as an anti-wear agent and friction reducer thatis compatible with conventional lubricant base fluids and whichovercomes the cost and solubility limitations of highly fluorinatedsolid and liquid materials. This object has been achieved innon-symmetric, partially fluorinated compositions and compounds of thepresent invention.

[0018] Thus, the present invention provides a composition for use as alubricant or an additive to a lubricant formulation comprising anorganic molecular structure wherein said structure is a non-symmetric,partially fluorinated structure having backbone formed from alkylgroups, aromatic groups or mixtures of alkyl and aromatic groups, atleast two functional linkages joining end groups to the backbone and endgroups, wherein at least one end group is wholly or partiallyfluorinated and at least one other end group contains only atomsselected from the group consisting of hydrogen, carbon, nitrogen,oxygen, sulfur, phosphorous and chlorine.

[0019] The functional linkages of the present invention contain atomsselected from the group consisting of oxygen, nitrogen, sulfur, andphosphorous. Preferred functional linkages include carboxylic esters,thioesters, sulfonic esters, ureas, thioureas, amides, phosphates,thiophosphates, imines, amines, ethers, thioethers, urethanes,thiourethanes, sulfoxides, and sulfones.

[0020] The present invention also provides a process for synthesizingthe present composition comprising the steps of:

[0021] a) forming a reaction mixture containing components A and B whichwhen reacted form functional linkages wherein A is a mixture of two ormore compounds containing at least one reactive functional groupselected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride, and further wherein at least one of said compounds of saidmixture is a partially fluorinated compound and at least one other ofsaid compound of said mixture is a non-fluorinated compound; and whereinB is a compound containing at least two reactive functional groups whichare the same or different and are capable of reacting with the reactivefunctional groups present in A and said reactive functional groups of Bare selected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride; with the proviso: (i) that when the functional groups ofeither A or B are alcohols, then the functional groups of B or A,respectively, are selected from the group consisting of (ii) that whenthe functional groups of either A or B are mercaptans, then thefunctional groups of B or A, respectively, are selected from the groupconsisting of acid halide, isocyanate and alkyl halide; and (iii) thatwhen the functional groups of either A or B are amines, then thefunctional groups of B or A, respectively, are selected from the groupconsisting of carboxylic acid, acid anhydride, acid chloride, carboxylicester, isocyanate, aldehyde and ketone; and

[0022] b. reacting the mixture to form the functional linkages, and

[0023] c. recovering a non-symmetric, partially fluorinated compositionhaving a molecular structure:

R_(1f)—F′—R₂—F″—R_(3h)

[0024] Where: R_(1f) represents a wholly or partially fluorinated C₁ toC₄₀ organic residue end group; F′ and F″ represent functional linkageswhich are either alike or different and are selected from the groupconsisting of carboxylic esters, thioesters, sulfonic esters, ureas,thioureas, amides, phosphates, thiophosphates, imines, amines, ethers,thioethers, urethanes, thiourethanes, sulfoxides, sulfones, and mixturesthereof; R₂ represents the hydrocarbon backbone selected from the groupconsisting of a C₁ to C₃₀ alkyl, cycloalkyl, and aromatic group andmixtures thereof; and R_(3h) represents a non-fluorinated C₁ to C₄₀organic residue end group.

[0025] The preferred structures for component A useful in the presentinvention include the following, where X represents an —OH, —SH, —NH₂ or—NHR′ group:

[0026] F(CF₂)_(x)CH₂X; H (CF₂)_(x)CH₂X, wherein x is 1 to about 20;mixtures of the telomers of F(CF₂CF₂)_(x)CH₂CH₂X, wherein x is 1 toabout 10 and preferably having an average x of from about 3.5 to about3.9; mixtures of the telomers of F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H, wherein xis 1 to about 10 and y is 1 to 20 and preferably having an average x ofabout 3.9 and an average y of about 8, and of the telomers ofF(CF(CF₃)CF₂O)_(x)CF(CF₃) CH₂X, wherein x is 1 to about 12 andpreferably having an average x of about 6.7.

[0027] The preferred structures for component B useful in the presentinvention include the difunctional carboxylic acid, acid anhydride, acidchloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride.

[0028] Diacids useful in the present invention include those having fromabout 4 to 24 carbons, the corresponding acid anhydrides and dimer acidshaving up to 36 carbons. Acid halides, sulfonyl halides, isocyanates,isothiocyanates, phosphoryl halides and thiophosphoryl halides havingstructures corresponding to these diacids are also useful in the presentinvention. Although the preferred structures of the compounds of thepresent invention are the structures having like functional groups,structures may have mixed functional groups, for example, carboxylicacid/sufonyl halide, carbonyl/carboxylic acid or other combinations.

[0029] The present invention includes a lubricant composition comprisinga base fluid mixed with the non-symmetric, partially fluorinatedcompounds of the present invention.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWING

[0030] FIGS. 1 shows friction and wear performance of ZDDP in 150N oil,for the purpose of comparison with the reduction in friction and wearobserved with compositions and compounds of the present invention.

[0031]FIG. 2 shows BOCLE wear as a function of the mole percent of thefluorinated telomer alcohol in the mixed alcohol reactant of Example 1.

[0032]FIG. 3 shows BOCLE wear performance as a function of the weightpercent of additive in 150N oil and as a function of the weight percentfluorine in the mixture of oil and additive the for the diester ofExample 2 prepared from reaction of Dodecanedioic acid (DDDA), telomeralcohol and Exxal 13.

[0033]FIG. 4 shows wear performance of the diester additive of Example 3as a function of the weight percent of additive in 150N oil and as afunction of the weight percent fluorine in the mixture of oil andadditive.

[0034]FIG. 5 shows a comparison of wear reduction of preparation 18,Example 3 to that of a commercially available non-fluorinated esteradditive as a function of the weight percent of additive present in theadditive/oil mixture.

[0035]FIG. 6 illustrates a triangular plot showing how the amount ofinsoluble solids (i.e., residue) varies with the composition of themixed amide-esters derived from primary amines of Example 6.

[0036]FIG. 7 illustrates a triangular plot showing how the amount ofinsoluble solids (i.e., residue) varies with the composition of themixed amide-esters derived from secondary amines of Example 6.

[0037]FIG. 8 shows wear performance of the diester additive of Example 7as a function of the weight percent of additive in 150N oil and as afunction of the parts per million of fluorine in the mixture of oil andadditive.

DETAILED DESCRIPTION OF THE INVENTION

[0038] The present invention provides a composition for use as alubricant or an additive to a lubricant formulation comprising anorganic molecular structure wherein said structure is a non-symmetric,partially fluorinated structure having backbone formed from alkylgroups, aromatic groups or mixtures of alkyl and aromatic groups, atleast two functional linkages joining end groups to the backbone and endgroups, wherein one end group is wholly or partially fluorinated and theother end groups contain only atoms selected from the group consistingof hydrogen, carbon, nitrogen, oxygen, sulfur, phosphorous and chlorine.For example, a molecular structure of the present invention may beillustrated as follows:

R_(1f)—F′—R₂—F″—R_(3h)

[0039] where R_(1f) represents a wholly or partially fluorinated organicresidue end group, F′ and F″ represent functional linkages which may bealike or different, R₂ represents the backbone and R_(3h) represents anon-fluorinated organic residue end group. The compounds correspondingto this molecular structure are defined for purposes of this inventionas being non-symmetric, partially fluorinated structures.

[0040] The functional linkages of the present invention contain atomsselected from the group consisting of oxygen, nitrogen, sulfur, andphosphorous. Preferred functional linkages include carboxylic esters,thioesters, sulfonic esters, ureas, thioureas, amides, phosphates,thiophosphates, imines, amines, ethers, thioethers, urethanes,thiourethanes, sulfoxides, and sulfones.

[0041] The preferred structures of the present invention includecompounds where F and F′ is the same linkage. R_(1f) and R_(3h) may be,but need not be alike.

[0042] By non-symmetric, partially fluorinated structure is meant anorganic compound having some of the hydrogen replaced by fluorine andhaving the fluorine concentrated in one region of the structure. Forexample, the following is a structure for a diester according to thepresent invention, R_(f)(CH₂)_(x)O₂C—R—CO₂R_(h), where R_(f) is a partlyor completely fluorinated group, R_(h) is a non-fluorinated group, andx≧1. Such diesters synthesized according to the process of the presentinvention may also contain non-fluorinated diesters,R_(h)O₂C—R—CO₂R_(h), and symmetrically-fluorinated diesters,R_(f)(CH₂)_(x)O₂C—R—CO₂(CH₂)_(x)R_(f) byproducts. In terms of structuralcomponents, R_(f) and R_(h) are end groups —R— is the backbone and —O₂C—is the functional linkage. The preferred backbone is formed from ahydrocarbon chain which may be alkyl, aromatic, or a mixture of alkyl(branched, cyclic or straight chains) and aromatic units. It ispreferred that unsaturation such as alkylene groups in the backbone beavoided if the additive is to be stable under conditions of use. Itshould be further appreciated that the backbone can optionally containmore than two functional groups and as such other B molecules such asneopentyl glycol, trimethylolproprane, pentaerythritol, and the like arecontemplated as being useful in the present invention.

[0043] The term base fluid means a lubricating material, liquid or solidused as the major component in a lubricant formulation. Base fluids arecombined with other substances to make fully formulated lubricants foruse in reducing friction and wear. A base fluid may be synthetic ornatural.

[0044] The non-symmetric, partially fluorinated compounds of the presentinvention may be derived, for example in the case of an ester, from adiacid, at least one partially fluorinated alcohol, R_(f)OH, and atleast one non-fluorinated alcohol, R_(h)OH, or their functionalequivalents. In this shorthand, R_(f) represents a partially or whollyfluorinated group and R_(h) represents a non-fluorinated group. Thefunctional linkage is the —COO— group forming the ester. The diesteraccording to the present invention is a mixture of at least 3 genericcomponents: R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f),R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(h), and R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f).Since in commercially available compounds R_(f)OH and R_(h)OH arethemselves generally mixtures, the diester products are even morecomplicated mixtures containing all possible combinations of R_(f) andR_(h). That is, each of the three generic components is itself amixture. R_(f) is derived from the partly-fluorinated alcohol, R_(h)from the non-fluorinated alcohol, and the central part of the diester,—O(O)C—(CH₂)_(x)—C(O)O— can be thought of as derived from a diacid,HO(O)C—(CH₂)_(x)—-C(O)OH.

[0045] The diester simply serves as an example of one of the manycompounds of the present invention. Other functional linkages may beformed in the same fashion as the ester functional linkage by properselection of the reaction components. For example, one component may berepresented by “A” and the other by “B”. The functional linkages areformed in the reaction of A with B. In all cases A represents a mixtureof the class or classes of compounds that are to be reacted with B; andA is a mixture of two or more compounds wherein at least one of thesecompounds is a partially fluorinated compound and the other compoundsare non-fluorinated compounds; with the proviso that when A is a mixtureof alcohols, B is an selected from the group consisting of diacids anddiacid equivalents, nitrites, sulfonyl halides, isocyanates,isothiocyanates, phosphoryl halides and thiophosphoryl halides; when Ais a mixture of mercaptans, B is selected from the group comprisingcarboxylic acid halides, isocyanates and alkyl halides; and when A is amixture of amines, B is selected from the group consisting of carboxylicacids and acid equivalents, isocyanates, aldehydes and ketones.

[0046] Again for illustration considering the reaction of a mixture ofalcohols (A) with a diacid or mixture of diacids (B), theoretically whenan alcohol mixture that is 50 mole percent non-fluorinated alcohol and50 mole percent fluorinated alcohol, the mole percent composition of themixed diester product is 50 mole percent non-symmetric, partiallyfluorinated diester, and 25 mole percent each symmetrically fluorinateddiester and hydrocarbon diester. As the composition of the alcoholmixture is changed with respect to the ratio of fluorinated tonon-fluorinated alcohol, the composition of the ester mixture resultingfrom the reaction changes according to the probability of producingdiesters of symmetric and non-symmetric structures. The inventor hasfound that the presence of the non-symmetric, partially fluorinateddiester in the mixed ester product of amounts as low as 1 mole percentproduces dramatic reduction in friction when the mixture is used aloneor formulated into a base fluid. That is to say that a mixturecontaining 1 mole percent of the compound of the present invention,present in a lubricant equal to about 0.2% fluorine content in theoverall lubricant formulation, results in a dramatic reduction infriction and wear. Also any composition of a resulting diester mixture,or other mixtures of the present invention, may be adjusted to reducethe amount symmetric, fluorinated diester present by dewaxing thecomposition, as is illustrated in the Examples below. End groups,backbones and function linkages of the present invention may be selectedaccording to the listing below. This listing is not exhaustive, butlists examples of functional linkages which provide ligands for metalsurfaces. For example, metal compositions present at typical steelsurfaces might comprise iron and various iron oxides as well as othermetals and oxides from other metallic components present in the steelalloy (most commonly other first-row transition metals, notably Cr andNi, though second-row and third-row metals may also be present).Effective ligands for such metal compositions include organic compoundscontaining atoms with unshared electron pairs which can serve as Lewisbase electron-pair donor ligands to form donor-acceptor bonds with metalcompositions. Thus, suitable functional linkages include any functionallinkage that forms an effective ligand with the surface of the substratethat is to be lubricated. In a sense the structures of the presentinvention may be thought of as a combination of a high lubricityfluorinated end, a functional linkage that both connects the end to thebackbone of the structure and forms a ligand-like association with thesurface to be lubricated and a hydrocarbon tail which providessolubility in the base fluid.

[0047] Selection of Structural Components: Functional Group 1 FunctionalGroup 2 F Linkage Alcohol Carboxylic acid, acid Carboxylic anhydrides,carboxylic ester esters, nitrile, or carboxylic acid halide (e.g.chloride) Mercaptan Carboxylic acid halide Thioester (e.g. chloride)Alcohol Sulfonyl halide (e.g. Sulfonic ester RSO₂Cl) Alcohol IsocyanateCarbamates (Urethanes) Alcohol Isothiocyanate Thiourethane AmineIsocyanate Urea Mercaptan Isocyanate Thiourea Amine Carboxylic acid,Amide Carboxylic acid halide or ester Alcohol Phosphoryl halide (e.g.Phosphate (O chloride) donor atoms) Alcohol Thiophosphoryl halideThiophosphate (e.g. chloride) (S or O donor atoms) Amine Carbonylcompound Imine, amine (aldehyde or ketone) (after reduction) AlcoholAlkyl halide Ether Mercaptan Alkyl halide Sulfide (Thioether) AlcoholPhosphoric anhydride Dialkylphosphor- ic acid ester AlcoholThiophosporic anhydride Dialkyl dithiophosporic acid ester Oxidation ofsulfides Sulfoxides and (see above) Sulfones

[0048] The previously known, symmetrical, highly-fluorinated compounds,for example, diesters, R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f), have lowsolubility in the mineral oils commonly used as lubricant base fluidsand poor low-temperature properties, which limits their use as lubeadditives. It is the mixed, non-symmetric, partially fluorinateddiesters, R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f), which is the main object ofthis invention. However, it is generally not necessary to separate thedesired non-symmetric, partially fluorinated diesters from the highlyfluorinated and non-fluorinated diesters products also present in thereaction mixture.

[0049] Although usually not necessary, if desired, the mixed products ofthe present invention may be purified by centrifugation, distillation,fractional crystallization, filtration, extraction, or other standardmethods known to those skilled in the art.

[0050] Preparation of the compositions of the present invention may beachieved, for example by 1) preparing the compounds of the inventionusing a limited, less than stoichiometric, amount of fluorinatedcomponent in the synthesis and 2) preparing the compounds of the presentinvention from a mixture of at least one fluorinated “A” compound andone non-fluorinated “A” compound, preferably a mixed-isomer, long-chain,non-fluorinated component of class “A”.

[0051] The process of the present invention comprises the steps of:

[0052] a) forming a reaction mixture containing components A and B whichwhen reacted form functional linkages wherein A is a mixture of two ormore compounds containing at least one reactive functional groupselected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride, and further wherein at least one of said compounds of saidmixture is a partially fluorinated compound and at least one other ofsaid compound of said mixture is a non-fluorinated compound; and whereinB is a compound containing at least two reactive functional groups whichare the same or different and are capable of reacting with the reactivefunctional groups present in A and said reactive functional groups of Bare selected either from the group consisting of alcohol, mercaptan andamine or from the group consisting of carboxylic acid, acid anhydride,acid chloride, carboxylic ester, nitrile, sulfonyl halide, isocyanate,isothiocyanate, aldehyde, ketone, alkyl halide, phosphoryl halide,thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride; with the proviso: (i) that when the functional groups ofeither A or B are alcohols, then the functional groups of B or A,respectively, are selected from the group consisting of carboxylic acid,acid anhydride, acid chloride, carboxylic ester, acid anhydride,nitrile, sulfonyl halide, isocyanate, isothiocyanate, phosphoryl halide,thiophosphoryl halide and alkyl halide; (ii) that when the functionalgroups of either A or B are mercaptans, then the functional groups of Bor A, respectively, are selected from the group consisting of acidhalide, isocyanate and alkyl halide; and (iii) that when the functionalgroups of either A or B are amines, then the functional groups of B orA, respectively, are selected from the group consisting of carboxylicacid, acid anhydride, acid chloride, carboxylic ester, isocyanate,aldehyde and ketone; and

[0053] d. reacting the mixture to form the functional linkages, and

[0054] e. recovering a non-symmetric, partially fluorinated compositionhaving a molecular structure:

R_(1f)—F—R₂—F′—R_(3h)

[0055] Where: R_(1f) represents a wholly or partially fluorinated C₁ toC₄₀ organic residue end group; F and F′ represent functional linkageswhich are either alike or different and are selected from the groupconsisting of carboxylic esters, thioesters, sulfonic esters, ureas,thioureas, amides, phosphates, thiophosphates, imines, amines, ethers,thioethers, urethanes, thiourethanes, sulfoxides, sulfones, and mixturesthereof; R₂ represents the hydrocarbon backbone selected from the groupconsisting of a C₁ to C₃₀ alkyl, cycloalkyl, and aromatic group andmixtures thereof; and R_(3h) represents a non-fluorinated C₁ to C₄₀organic residue end group.

[0056] The reaction used to form the functional linkage from componentsA and B may be any of the methods known in the art. In some casesparticular reaction methods may be more favorable because of rate, andor the ability to remove unwanted byproducts such as water.

[0057] As the fluorinated component of the mixture “A”, alcohols may bemore easily found since there are several types commercially available.Examples of common partly-fluorinated alcohols useful in the presentinvention include 1H, 1H, 2H, 2H-perfluoroalkanols, whereF(CF₂CF₂)_(x)CH₂CH₂OH, are preferred, with mixtures where x is at least1; F(CF₂)_(x)CH₂OH alcohols, for example, 1H, 1H-heptafluoro-1-butanol;and 1H, 1H-perfluoro-1-octanol; H(CF₂)_(x)CH₂OH alcohols, for example,1H, 1H, 5H-octafluoro-1-pentanol; F(CF₂CF₂)_(x)CH₂CH₂OH alcohols, forexample, 1H, 1H, 2H, 2H-perfluoro-1-octanol mixtures with average x ofabout 3.5 or about 3.9 (referred to as Telomer alcohol-L and Telomeralcohol respectively); F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H, generally mixtureswith average x of about 3.9 and y about 8, for example, Telomerethoxylate alcohol; and F(CF(CF₃)CF₂O)_(x)CF(CF₃) CH₂OH, generallymixtures with average x of about 6.7, for example, poly HFPO alcohol. Inthe present process one may also use as components of the mixture “A”,mercaptans or amines having structures similar to or derived from theavailable alcohols; for example, F(CF₂CF₂)_(x)CH₂CH₂SH and F(CF₂CF₂)_(x)CH₂CH₂CH₂NH₂.

[0058] Virtually any non-fluorinated compound of class “A” may be usedto prepare the non-symmetric, partially fluorinated compounds of thepresent invention. The non-fluorinated alcohols preferred for thisinvention are those commonly used in lubricant ester fluids, typicallyhigher aliphatic alcohols such as those described in Kirk Othmer, Volume1 (1991). These include mixtures, such as Exxal 13, tridecyl alcohol,manufactured by Exxon, indicated on the Material Safety Data Sheet to be“Alcohols, C11-C14, iso.” Such alcohols produce esters with desirablephysical properties to be used as lubricants and lubricant additives.

[0059] In the cases where amines or mercaptans serve as thenon-fluorinated component of mixture “A”, one may use any suitableamines or mercaptans. Those having structures corresponding to orderived from the available alcohols described in the paragraphimmediately above are preferred.

[0060] The preferred diacids for the present invention are those diacidscommonly used in forming lubricant ester fluids. These are most commonlystraight chain diacids, HO(O)C—(CR₂)_(x)—C(O)OH, wherein each R isindependently selected from H or C₁ to C₄ alkyl group. Most commonly,all R=H and x=1 to about 12. The most available and widely used diacidsare adipic, azelaic, sebacic, and dodecanedioic acids, which contain 6,9, 10, and 12 carbons respectively. However branched structures such as2-methylglurtaric acid are acceptable. Also, two or more R may beconjoined to form cyclic structures such as in C₃₆ “dimer acid.”Mixtures of diacids may be used, such as C₃₆ “dimer acid” or CORFREE®M1, from Dupont, which is a mixture of mainly C₁₀-C₁₂ diacids. Preferreddiacids include adipic, 2-methylglutaric, 2-ethylsuccinic, CORFREE M1and longer chain acids such as Dodecanedioic acid (DDDA). Selection ofdiacid and other “B” group chain lengths will depend on the lubricantapplication for which the additive is to be used. In liquid lubricantformulations the “B” group chain length, in combination with thenon-fluorinated “A” group is selected so that the additive is soluble inthe liquid base fluid. For solid lubricants, the chain lengths can besuch that the additive is either a liquid or solid, which is soluble orcompatible with the base fluid. It may even be desirable to use acomposition of the present invention alone as a lubricant.

[0061] It should be further appreciated that either A or B or both maybe optionally substituted with functional groups which do not interferein the reaction of A with B to form the desired functional linkages. Forexample, the respective components may contain ether linkages, such asin ethoxylated or propoxylated animes or alcohols, or ether amines suchas ROCH₂CH₂CH₂NH₂. They may also contain linear, branched or cyclicarrangements of atoms and may contain more than one branched groups thatmay be the same or different.

Test Methods

[0062] Samples were tested using the ball-on-cylinder (BOCLE) test,described in ASTM D5001. Wear was quantified by the size of the wearscar on the ball, measured at the end of the test. A smaller wear scarindicated less wear. The coefficient of friction was calculated from theratio of the tangential (lateral) force on the ball to the downward(normal) force on the ball. In all cases, the normal force was 12,00grams (see Table 1). Several modifications were made to the test, assummarized in Table 1. These changes are expected to make the test amore severe test of anti-wear and friction modifying properties, asdescribed below. TABLE 1 Ball-on-cylinder test conditions. Standard ASTMD5001 Modified D5001 (consequence) 0.5″ ball 0.25″ ball (smaller contactarea) 25° C. 80° C. (lower lubricant viscosity) 1000 g load, 30 500 gbreak in load, 0.5 minute, minutes followed by 6000 g test load, 30minutes (higher contact pressure; note that a 6000 g load produces a12,000 g normal force at the ball- cylinder contact point) No frictiondata Calibrated load cell to measure tangential force on ball duringtest (allows calculation of coefficient of friction from ratio oftangential force to normal force, 12,000 g)

[0063] The relative performance of the materials of the presentinvention was evaluated as additives in a mineral oil base fluid. Acommonly available high-quality solvent-refined 150 neutral oil (150N)available from Conoco (about ISO 32 viscosity grade) was selected as themineral oil base fluid. A grade of oil such as 150N might be used as onecomponent for blending of an oil for use in an internal combustionengine. 150N contains no additives. This 150N oil was tested accordingto the modified BOCLE method numerous times, the average of theseresults is summarized in Table 2. TABLE 2 Solvent refined 150N oil BOCLEresults Solvent-refined Coefficient of Wear scar, 150N oil friction mmNumber of 9 13 measurements Average 0.1424 0.851 Standard 0.0052 0.042deviation 95% Confidence ±0.00399 ±0.025 interval

[0064] For comparative purposes, the friction and wear performance ofseveral fully formulated (ILSAC GF-1), commercially available passengercar motor oils were measured. The oils tested included two leading fullsynthetics (MOBIL 15W30, Castrol SYNTEC 5W50) and one conventionalnon-synthetic oil (MOTORCRAFT 5W30). Performance of all three oils wasvery similar, as summarized in Table 3. This may be because all threecontain similar amounts of zinc dialkyldithiophosphate (ZDDP), anextremely effective anti-wear agent. The effect of varying concentrationof ZDDP (“Elco 106” purchased from Ideas, Inc.) is shown in FIG. 1. Thedata in this Figure serves as to provide a standard for comparison ofthe improvement in lubrication achieved by mixing a hydrocarbonlubricant with the non-symmetric partially fluorinated compositions ofthe present invention. TABLE 3 Commercially Available GF-1 Motor OilBOCLE Test Results Formulated GF-1 Coefficient of Wear Motor oilsfriction scar, mm Number of 2 9 measurements Average 0.1313 0.499Standard 0.0029 0.029 deviation 95% Confidence ±0.0260 ±0.022 interval

[0065] To determine the efficacy of the additives made according to thepresent invention, their effect on friction and wear was measured as afunction of their concentration in the standard 150N oil. Note thatthere are two approaches to obtaining a given level of fluorine in ablended lubricant. An additive containing a high level of fluorine canbe used at a low treat rate or an additive containing a low level offluorine can be used at a high treat rate. These two approaches do notnecessarily give the same performance.

[0066] The following Examples illustrate the present invention, but arenot intended to be limiting.

EXAMPLE 1

[0067] The following Example describes the condensation esterificationof DDDA using Fascat 2003 catalyst, a tin-based esterification catalystfrom Elf Atochem, and the preparation of DDDA diesters with varying molepercent Telomer alcohol and Exxal 13.

[0068] Reaction mixtures were prepared in 20 mL vials with thecompositions indicated in table 4 below. One drop of Fascat 2003 (aproduct of Atochem) was added to each vial, and the reactions wereheated at 200-250° C. for about 12 hours under a nitrogen sweep toremove evolved water. GC analysis of the reaction mixtures showed theexpected three component ester mixture: R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f);R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(h); and R_(h)O(O)C—(CH₂)_(x)—C(O)OR_(f).The actual amount of each ester component present varied as expectedwith the relative amounts of Telomer alcohol and Exxal 13 present in thesynthesis mixture. The appearance of the mixture formed from therespective additive and 150N oil as well as the solubility of theadditive in 150N oil are also summarized in the Table 4. It isnoteworthy that the fully fluorinated diester, vial 8, was more solublewhen heated, but that the solution cooled to a gel-like state as thediester reprecipitated with cooling. Such behavior is very undesirablein a lubricant. This illustrates an important deficiency of the fullyfluorinated diesters, since lubricants are often subjected totemperature cycling, and low-temperature performance is often critical.TABLE 4 DDDA diesters with Telomer alcohol and Exxal 13 mol % TelomerSolubility in Telomer Exxal alcohol 150 N DDDA alcohol 13 vs total oilat No. (mmol) (mmol) (mmol) alcohol Appearance 25° C. 1 5.15 0.29 10.743 liquid ≧20% 2 4.94 0.58 10.51 5 liquid 3 5.15 1.34 9.88 12 honey- >1%like 4 5.05 2.4 8.81 21 very thick oil 5 5.05 4.4 6.62 40 grease ≦0.5%like 6 5.13 5.62 5.47 51 grease ≈0.25% like 7 5.15 8.26 2.78 75 beeswaxlike 8 5.34 11.06 0 100 paraffin ≦0.1% like

[0069] Wear test results for some of the above materials are shown inFIG. 2. It is clear from this figure that most of the wear benefit isachieved with only about 20 mole % Telomer alcohol in the diester. Thewear response, quite surprisingly, is extremely non-linear. This iscontrary to the linear response that might be expected if thewear-reducing effects were simply the net average from the concentrationpresent of completely fluorinated diester (100% Telomer alcohol) andnon-fluorinated ester (0% Telomer alcohol). This implies that thenon-symmetric, partially fluorinated diesters of the present inventionhave better wear reducing properties than either the non-fluorinated orcompletely fluorinated diesters.

EXAMPLE 2

[0070] The following Example describes the condensation esterificationof DDDA using p-toluenesulfonic acid catalyst and the preparation ofDDDA diester using a mixture of 50 mole % Telomer alcohol and 50 mole %Exxal 13 followed by a “dewaxing” hexane extraction to remove thesymmetrically fluorinated component from the mixed ester product.

[0071] A mixture of 230.3 g DDDA (1.0 mole), 474.64 g Telomer alcohol(1.05 mole), 207.91 g Exxal 13 (1.05 mole), and 1.9 g p-toluenesulfonicacid (0.01 mole) were charged to a reactor fitted with a Dean-Stark trapand condenser. The Dean-Stark trap was filled with additional Exxal 13.The reaction was heated and sparged with nitrogen to remove water. Thenitrogen sparge was removed and the reaction heated to 280° C. undervacuum (≦0.07 kPa). A portion of the crude ester (610 g) was stirredwith 1700 g hexane. The hexane solution was decanted and filtered fromundissolved, highly fluorinated material. The hexane solution wastreated with activated charcoal and filtered, then with basic aluminaand filtered again. Hexane was removed by distillation. Elementalanalysis of the residue showed 29.56%F, in good agreement with 28.3%F by¹H NMR analysis.

[0072]FIG. 3 shows the wear performance of this high-F-content materialin 150N oil. The range of fluorine concentrations shown in FIG. 3corresponds to weight concentrations of diester ranging up to 1%.Samples of 150N containing 0.25% diester (equivalent to 0.07%F) or morewere hazy at ambient temperature, due to the limited solubility of thehighly fluorinated diester component, R_(f)O(O)C—(CH₂)_(x)—C(O)OR_(f),but were homogeneous at the 80° C. BOCLE test temperature. The responseis very non-linear. A very strong anti-wear effect is obtained with onlyvery small concentrations of the additive. The properties of the mixtureof 150N oil and additive are much better than the properties expectedbased on simple linear effects and overall composition. The anti-wearperformance achieved in FIG. 3, through use of the non-symmetrical,partially fluorinated diesters of the present invention, without otheradditives, is comparable to that of fully formulated motor oil.

EXAMPLE 3

[0073] The following Example describes the condensation esterificationof DDDA using methanesulfonic acid catalyst and the preparation of DDDAdiester using a mixture of 50 mole % Telomer alcohol-L and 50 mole %Exxal 13.

[0074] A 500 mL round bottom flask was charged with 69.06 g DDDA (MW230.3, 0.3 mole), 130.41 g Telomer alcohol-L (average molecular weight414, 0.315 mole), 62.37 g Exxal 13 tridecyl alcohol from Exxon (FW 198,0.315 mole), 0.29 g methanesulfonic acid (MW 96.1, 0.003 mole), and 100g mixed xylenes. The reaction flask was fitted with an 8″ Vigreux columntopped with a Dean-Stark trap and condenser. The reaction was heated toreflux to drive off water, which was separated in the Dean-Stark trap,xylene overflow being returned to the reaction flask. The reaction wasfollowed by water removal and by periodic sampling and titration foracid number.

[0075] After 10 and ½ hours reaction time, the acid number had decreasedto 1.6 mg KOH/g, and the reaction was considered to be complete.

[0076] The reaction product was brown. The reaction product was washed,at 70-80° C., with 330 g of 0.2% aqueous sodium hydroxide. Phases wereinverted, with a brown aqueous phase on top and the denser ester phaseon the bottom. The lower ester phase was very cloudy. After separatingthe caustic wash, the ester phase was washed three times with 300 mLportions of warm water. The acid number was 0.56 mg KOH/g.

[0077] The crude ester was sparged with nitrogen and heated from roomtemperature to a temperature of 210-220° C. over a period of 90 minutesto remove xylene, water, and other low boilers.

[0078] The yield was 215.72 g of a waxy tan solid having an acid number0.75 mg KOH/g.

[0079] The same basic procedure as above was used to prepare otherpartially fluorinated esters, listed in Table 5. In all cases, thenon-fluorinated alcohol was Exxal 13, tridecyl alcohol from Exxon. Dueto difficulty obtaining reliable F elemental analysis, ester end groupswere also analyzed by ¹H NMR. The chemical shift region between 3.5 and4.5 ppm downfield of tetramethylsilane reveals the CH₂ protons attachedto the ester oxygen. In the case of R_(f), these CH₂ protons are cleanlyseparated and downfield from the CH₂ protons of R_(h). The relativemolar amounts of R_(f) and R_(h) can be calculated from the integrals ofthese two groups. Where elemental analysis and NMR disagree, the NMRmethod is believed to be more reliable. Table 5. Partially fluorinatedesters prepared by condensation esterification using methanesulfonicacid catalyst Mole fraction Acid Wt % F Partially partially number(elemental Wt % Prepara- Fluorinated fluorinated (mg F (by tion Diacidalcohol alcohol KOH/g) analysis) NMR) 9 Adipic Telomer 0.025 0.34 1.922.6 alcohol-L 10 Adipic Telomer 0.025 0.29 2.25 3.2 alcohol 11 AzelaicTelomer 0.025 0 1.83 1.66 Alcohol-L 12 C14 Telomer 0.025 0.27 1.39 1.28diacid alcohol-L 13 Corfree Telomer 0.025 0 1.23 1.39 M1 alcohol-L 14Corfree Telomer 0.025 0.6 1.32 1.49 M1 alcohol-L 15 DDDA Poly HEPO 0.0250.1 4.17 alcohol 16 DDDA Telomer 0.025 alcohol 17 DDDA Telomer 0.0250.55 2.1 2.4 alcohol 18 DDDA Telomer 0.025 0.131 1.86 2 alcohol 19 DDDATelomer 0.023 0.1 0 0 alcohol 20 DDDA Telomer 0.024 0 0 0 alcohol 21DDDA Telomer 0.025 0.18 1.87 2.1 alcohol-L 22 DDDA Telomer 0.125 0.243.01 9.47 alcohol-L 23 DDDA Telomer 0.05 0.2 4.06 alcohol-L 24 DDDATelomer 0.025 0.18 1.82 1.92 alcohol-L 25 DDDA Telomer 0.25 0.3 16.6817.3 alcohol-L 26 DDDA Telomer 0.5 0.751 34.6 34.3 alcohol-L 27 DDDATelomer 0.025 0.27 2.36 3.4 ethoxylate alcohol 28 Sebacic Telomer 0.0250.2 1.58 1.63 alcohol-L 29 Suberic Telomer 0.025 0.26 0.72 1.91alcohol-L

[0080]FIG. 4 shows the wear and friction performance of a low-F-contentmaterial (≈2% F), sample 18 in Table 5, in 150N oil. This low-F-contentmaterial was completely soluble even at 20% by weight concentration (0.4wt. percent F). FIG. 5 compares the anti-wear performance of this low-Fmaterial to a similar non-fluorinated diester, ditridecyl dodecanedioate(Hatcol 2907, from Hatco), showing the significant improvement in wearperformance from only a very small amount of F incorporation.

[0081] Anti-wear and friction reducing performance of different chainlength diesters from C₆ to C₁₄ was compared. All of these non-symmetric,partially fluorinated diesters imparted some benefits, with the longerchain diacids giving the greater benefits. Therefore, the preferrednumber of carbon atoms in the backbone is 9 or more or the wear scar bythe BOCLE test as described herein is less than about 0.75 when theadditive is present at about 0.2% fluorine.

EXAMPLE 4

[0082] The following Example describes the transesterification ofdimethyl dodecanedioate using p-toluenesulfonic acid catalyst and thepreparation of DDDA diester using a mixture of 50 mole % Exxal 13 and 50mole % 1H, 1H, 5H-octafluoro-1-pentanol.

[0083] A mixture of 51.68 g dimethyl dodecanedioate (0.2 mole), 41.58 gExxal 13 (0.21 mole), 48.73 g 1H, 1H, 5H-octafluoro-1-pentanol (0.21mole), and 0.38 g p-toluenesulfonic acid was heated, and methanoldistilled off. When the reaction temperature reached 198° C., GCanalysis showed the dimethyl dodecanedioate to be essentially gone,indicating that the reaction had gone nearly to completion. Aftercooling, the product was washed with brine, 1% aqueous NaOH, and water,then treated with basic alumina and filtered. The final acid number was≦0.1 mg KOH/g.

[0084] The same basic procedure was used to prepare other diesters,listed in Table 6. The non-fluorinated alcohol was Exxal 13 in allcases. TABLE 6 DDDA diesters prepared according to Example 4. Molefraction Acid Partially partially number Wt % F Wt % F Prepara-Fluorinated fluorinated (mg (elemental (by tion alcohol alcohol KOH/g)analysis) NMR) 30 Telomer 0.025 1.12 1.24 alcohol-L 31 1H, 1H, 5H- 0.50.1 octafluoro-1- pentanol 32 1H, 1H, 2H, 0.5 0.1 2H-perfluoro-1-octanol 33 1H, 1H 0.5 0.1 heptafluoro- 1-butanol 34 1H, 1H- 0.5 0.1perfluoro-1- octanol 35 Telomer 0.025 2 alcohol 36 Telomer 0.025 0.521.45 1.63 alcohol

COMPARATIVE EXAMPLE 1

[0085] The following comparative Example describes the preparation ofdi(telomer alcohol)2-methylglutarate by one-step esterification of2-methylglutaronitrile (MGN).

[0086] A mixture of 32.44 g MGN (0.3 mole), 18.05 g water (1 mole), and304.2 g Telomer alcohol (0.67 mole) was preheated to 60° C., then 60.0 gsulfuric acid (0.61 mole) was added cautiously. The H₂SO₄ was added over≈30 minutes to maintain reflux. After the acid was added, the reactionwas refluxed for an additional 3 hours. The crude ester was decantedfrom the ammonium bisulfate salt phase while warm, then washed with 5%aqueous sodium bicarbonate. The product was dried by heating to 100° C.under reduced pressure (0.1 kPa) The product was a tan, waxy solid witha wide melting range (≈45-70° C.). Solubility in 150N oil was found tobe only <0.1% at ambient temperature.

EXAMPLE 5

[0087] This Example describes the esterification of2-methylglutaronitrile (MGN) in a two-step reaction:

[0088] A mixture of 43.26 g MGN (0.4 mole) and 36.0 g water (2 mole) waspreheated to 850C. Sulfuric acid (80.42 g, 0.82 mole) was added viadropping funnel, at a rate adjusted to maintain reaction temperature at115-135° C. Following the addition, the reaction was held at temperaturefor 1 hour, then cooled to 100° C. A mixture of 9.49 g Telomer alcohol(0.021 mole) and 162.16 g Exxal 13 (0.819 mole) was added over 7minutes, then the reaction was heated and held in the range 127-135 for1 hour. After cooling, the crude ester was decanted from ammoniumbisulfate salts. The crude ester was mixed with 100 g mixed xylenes and0.38 g methanesulfonic acid, placed in a reactor fitted with a Vigreuxcolumn and Dean-Stark trap, and heated to reflux to drive off water tocomplete the esterification. The reaction was sampled periodically andacid number determined. When the acid number had leveled off, indicatingthat no further reaction was occurring, the heat was turned off. Theproduct was washed with an equal volume of 0.5% NaOH solution, then 5times with water. Warming the mixture to 60° C. during the water washesimproved phase separation. The washed ester was sparged with nitrogenwhile being heated to 200° C. to drive off water. The final acid numberwas 0.15 mg KOH/g.

[0089] 2-Methylglutarate diesters prepared according to Comparativeexample 1 and example 5 are summarized below in Table 7. In all cases,the non-fluorinated alcohol was Exxal 13. TABLE 7 Mole fraction AcidPartially partially number Wt % F Wt % F Prepara- Preparationfluorinated fluorinated (mg (elemental (by tion method alcohol alcoholKOH/g) analysis) NMR) 37 5 Telomer 0.025 0.15 1.98 2.06 alcohol 38 5Telomer 0.025 0.19 1.13 1.2 alcohol-L 39 Comparative Telomer 0.5 0.07example 1 alcohol 40 Comparative Telomer 1 example 1 alcohol 41 5Telomer 0.05 2.4 1.16 2.9 alcohol-L 42 5 Telomer 0.125 0.3 5.33 8.56alcohol-L

[0090] The following examples 6 and 7 show that partially-fluorinatedamide-esters can be prepared which have solubility in conventionalmineral oil and that these partially fluorinated amide-esters can beused as lubricant additives to reduce friction and wear.

EXAMPLE 6

[0091] Preparation and Solubility of Partially-Fluorinated Amide-Estersfrom Dodecanedioic Acid, Tridecyl Alcohol, and Zonyl BAPartially-Fluorinated Alcohol:

[0092] A set of screening experiments was conducted to preparepartially-fluorinated amide-esters from dodecanedioic acid (DDDA) forassessing their solubility in non-polar, non-hydrogen-bonding solventssuch as mineral oils The alcohols used in this series of reactions weretridecyl alcohol (Exxal 13 from Exxon) and the partially-fluorinatedalcohol, Zonyl BA (from Dupont). Several amines were used, includingArmeen 2HT, Armeen HTMD, and Armeen 18D (from Akzo Nobel Chemicals) andAdogen 101, and Adogen 140 (from Sherex/Witco). These amines aredescribed in table 8 below. TABLE 8 Amine (CAS Description (type ofamine, formula number) estimated from ¹H NMR) Armeen 2HT Di(hydrogenated tallowalkyl)amine (R₂NH, (61789-79-5) average R =C_(17.6)H_(36.2)) Armeen HTMD Hydrogenated tallowalkylamine (RNH₂,(61788-45-2) average R = C_(17.5)H₃₆) Armeen 18D (124- Octadecyl amine(RNH₂, R = C₁₈H₃₇) 30-1) Adogen 101 C₁₆-C₂₂ amine (RNH₂, average R =C_(20.3)H_(41.6)) (68037-92-3) Adogen 140 Hydrogenated tallowalkylamine,also (68037-91-2) indicated to be C₁₄ to C₁₈ amine (RNH₂, average R =C_(18.1)H_(37.2))

[0093] Each reaction employed 1 mmol of DDDA, but the amounts of theother reactants were systematically varied as follows. The mole ratio ofExxal 13/DDDA was varied between 0 and 1.34, the mole ratio of ZonylBA/DDDA was varied between 0 and 1, and the mole ratio of amine/DDDA wasvaried between 0.33 and 2.0, under the constraint that the mole ratio ofthe total amount of alcohol and amine together was restricted to thetheoretically-required 2.0 moles per mole DDDA.

[0094] More specifically, for the case where the amine tested was Armeen2HT, the following eight reaction mixtures in table 9 were prepared,where the numbers represent the amount of each ingredient used, in mmol(except for the methanesulfonic acid esterification catalyst, which wasused in 10 μl quantity in each mixture). TABLE 9 Rx Rx Rx Rx Rx Rx Rx RxIngredient #1 #2 #3 #4 #5 #6 #7 #8 DDDA 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0Exxal 13 0.66 1.34 0.67 0.5 1.34 Zonyl BA 0.66 0.33 0.66 1.0 1.0 Armeen1.34 1.34 0.33 0.67 1.0 0.5 0.66 2.0 2HT Methanesu- 10 10 10 10 10 10 1010 lfonic μl μl μl μl μl μl μl μl acid (catalyst)

[0095] A similar set of eight reactions was prepared for each of thefive amines tested, for a total of 40 reaction mixtures.

[0096] The reaction mixtures were prepared in 2 mL glass vials.Reactions were conducted by placing the open-topped vials in a heatedblock maintained at 150° C. and maintaining that temperature for atleast 18 hours (generally 18-24 hours). This was intended to allowescape of water formed from the esterification and amidation reactions.The crude reaction products were used without purification forsolubility testing.

[0097] Relative solubility of the products from these reactions wasassessed by mixing the reaction product with 30 ml tetrahydrofuran(THF), then collecting and weighing any undissolved material on a 0.2 μmTeflon®-coated fiberglass membrane filter. The products from Armeen HTMDand Adogen 140, both hydrogenated tallowalkylamine, were judged to bevery similar, so the Armeen reactions were not filtered. Residue weightsare given in the table 10 below. TABLE 10 Rx Rx Rx Rx Rx Rx Rx Rx Amine#1 #2 #3 #4 #5 #6 #7 #8 Armeen 2HT 0.05 0.18 0 0 0.05 0.02 0 0.56 Armeen18D 0.43 0.37 0.06 0.15 0.24 0.12 0.14 0.48 (Not 1) Adogen 101 0.61 0.460.05 0.13 0.34 0.08 0.04 0.91 Adogen 140 0.35 0.85 0.04 0.16 0.17 0.070.07 0.97 Average of 0.46 0.56 0.05 0.15 0.25 0.09 0.08 0.79 Armeen 18D,Adogen 101, and Adogen 140 #which was incompatible with the THF solvent.The filter membrane was partially dissolved and some of the #insolublematerial was lost, so the 0.48 g represents the minimum quantity ofundissolved solid present in #the original THF mixture.)

[0098] By examining the results in the table, it is clear that theamides prepared from the primary amines Armeen 18D, Adogen 101, andAdogen 140 have similar solubility properties while the amides preparedfrom the secondary amine Armeen 2HT have significantly higher solubility(less insoluble residue). It is possible to prepare amide-esters withsignificant amounts of fluorinated ester groups which still have goodsolubility, particularly using the secondary amine Armeen 2HT (reactions5 and 6). The mole ratio of reaction 3 provided products, which werealmost completely soluble, even in the case of the primary amines. It isalso clear that the diamides have lower solubility (reaction 8 results).

[0099] To help visualize and interpret these results, the solubilitydata was evaluated using an experimental design software package, ECHIP(ECHIP, Inc., 724 Yorklyn Road, Hockessin, Del., 19707). The model usedwas an interaction model, which considers dependence on individualcomponents (e.g. amine content) as well as interactions (e.g. crossterms such as amine×Exxal 13). FIGS. 6 and 7 illustrate the ECHIP modelresults showing how the amount of insoluble solid varies with on thecomposition of the amide-ester. In the figures, end group composition isnormalized to 1.0; for example, the ester amide with equal amounts ofZonyl, Exxal, and amide end groups would lie at the center of thetriangle (0.33 mole fraction of each end group).

[0100] From these triangle plots, several conclusions can be drawn: (1)It is possible to prepare partially-fluorinated mixed ester amides whichhave good solubility in THF, (2) the amount of amine present in thecomposition (resulting in amide ends) has a major effect on solubility,with the least amount of insoluble solid being present at the lowestamide content, (3) compositions in the center region of thethree-component composition space have highest solubility in THF.

[0101] Since the mole ratio of reaction 3 provided products which werealmost completely soluble, even in the case of the primary amines, thisreactant ratio was chosen for scaleup. One example is given below.

EXAMPLE 7

[0102] Preparation of Ester Amide from Dodecanedioic Acid, Zonyl BA,Tridecyl Alcohol, and di(Hydrogenated Tallowalkyl)Amine:

[0103] A mixture of 46.06 g DDDA (0.200 mole), 60.98 g tridecyl alcohol(Exxal 13 from Exxon, 0.308 mole), 31.68 g Zonyl BA (0.066 mole), 33.67g Armeen 2HT (0.066 mole), 10 g Dowex 50W X2-400 strong acid ionexchange resin (used as esterification-amidation catalyst), and 63.84 gcyclohexane was heated to reflux. The mole ratio of the reactants used,DDDA:Exxal:Zonyl:Armeen was 1.0:1.54:0.33:0.33, is similar to screeningreaction #3 above example 6, except that the amount of Exxal wasincreased to ensure complete reaction and to increase reaction rate.Water was separated from refluxing cyclohexane using a condenser andDean-Stark trap. The reaction temperature was initially about 100-105°C. Water was drained from the trap and cyclohexane was added asnecessary to maintain reaction temperature at or below 118° C. After 25hours total reaction time, the acid number was 58. The reaction wasfiltered to remove the Dowex catalyst. The filtered crude product washeated to 200° C. while sparging with nitrogen, then the pressure wasreduced to 50 torr while continuing the nitrogen sparge. The purpose ofthis stripping procedure was to continue the reaction and to removeexcess, unreacted Exxal 13. The stripping procedure was continued forabout 7 hours, when analysis by gas chromatography showed that residualExxal 13 had been removed. The acid number had decreased to 19.

[0104] The product was analyzed by ¹H NMR, which was interpreted asfollows. A triplet at 4.4 ppm was assigned to the O—CH₂— protons of aZonyl ester end. A group of broad mulitplets between about 3.8 and 4.2ppm was assigned to the O—CH₂— protons of Exxal ester ends (manydifferent structures because Exxal 13 is a complex mixture). A pair ofmulitplets centered around 3.25 ppm was assigned to the —N—CH₂— protonsof an amide end derived from the Armeen 2HT. Integration of thesesignals suggested a composition of about 5.2% Zonyl ends, 80.7% Exxalends, and 14.2% Armeen amide ends (composition normalized to 100%),which suggested a fluorine content from the Zonly ends of 4.8% F.Elemental analysis showed 4.96%F.

[0105] This material was tested using the BOCLE procedure describedpreviously. Results are shown in FIG. 8.

[0106] Having thus described and exemplified the invention with acertain degree of particularity, it should be appreciated that thefollowing claims are not to be so limited but are to be afforded a scopecommensurate with the wording of each element of the claim andequivalents thereof.

I claim:
 1. A process for preparing a non-symmetric, partiallyfluorinated composition having a molecular structure:R_(1f)—F′—R₂—F″—R_(3h) wherein R_(1f) represents a wholly or partiallyfluorinated C₁ to C₄₀ organic residue end group; F′ and F″ representfunctional linkages which are either alike or different and are selectedfrom the group consisting of carboxylic esters, thioesters, sulfonicesters, ureas, thioureas, amides, phosphates, thiophosphates, imines,amines, ethers, thioethers, urethanes, thiourethanes, sulfoxides,sulfones, and mixtures thereof; R₂ represents the hydrocarbon backboneselected from the group consisting of a C₁ to C₃₀ alkyl, C₃ to C₃₀cycloalkyl, an aromatic group and mixtures thereof; and R_(3h)represents a non-fluorinated C₁ to C₄₀ organic residue end group, saidprocess comprising: (i) combining A and B, wherein A itself is a mixtureof two or more compounds wherein at least one A compound is a partiallyfluorinated compound and at least one other A compound is anon-fluorinated compound, and wherein B is a compound having at leasttwo functional groups that are the same or different, and wherein A andB independently are selected from the group consisting of (a) alcohol,mercaptan and amine, or (b) carboxylic acid, carboxylic acid anhydride,carboxylic acid halide, carboxylic ester, nitrile, sulfonyl halide,isocyanate, isothiocyanate, aldehyde, ketone, alkyl halide, phosphorylhalide, thiophosphoryl halide, phosphoric anhydride, and thiophosphorylanhydride, with the provisio: (i) that when the functional groups ofeither A or B are alcohols, then the functional groups of B or A,respectively, are selected from the group consisting of carboxylic acid,acid anhydride, acid chloride, carboxylic ester, acid anhydride,nitrile, sulfonyl halide, isocyanate, isothiocyanate, phosphoryl halide,thiophosphoryl halide and alkyl halide; (ii) that when the functionalgroups of either A or B are mercaptans, then the functional groups of Bor A, respectively, are selected from the group consisting of acidhalide, isocyanate and alkyl halide; and (iii) that when the functionalgroups of either A or B are amines, then the functional groups of B orA, respectively, are selected from the group consisting of carboxylicacid, acid anhydride, acid chloride, carboxylic ester, isocyanate,aldehyde and ketone; to form said F′ and F″ functional linkages (ii)recovering non-symmetric, partially fluorinated composition.
 2. Aprocess of claim 1 wherein Rlf is derived from: (i) F(CF₂)_(x)CH₂X orH(CF₂)_(x)CH₂X where x is 1 to 20; (ii) F(CF₂CF₂)_(x)CH₂CH₂X where x is1 to 10; (iii) F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H where x is 1 to 10 and y is 1to 20; (iv) F(CF(CF₃)CF₂O)_(x)CF(CF₃)CH₂X where x is 1 to 12; and (v)mixtures thereof wherein X is —OH, —SH, —NH₂ or —NHR′ where R′ is C₁ toC₄₀ alkyl.
 3. A process of claim 2 wherein X is —OH and F′ and F″ arecarboxylic esters.
 4. A non-symmetric, partially fluorinated compoundhaving a molecular structure: R_(1f)—F′—R₂—F″—R_(3h) wherein R_(1f)represents a wholly or partially fluorinated C₁ to C₄₀ organic residueend group; F′ and F″ represent functional linkages which are eitheralike or different and are selected from the group consisting ofcarboxylic esters, thioesters, sulfonic esters, ureas, thioureas,amides, phosphates, thiophosphates, imines, amines, ethers, thioethers,urethanes, thiourethanes, sulfoxides, sulfones, and mixtures thereof; R₂represents the hydrocarbon backbone selected from the group consistingof a C₁ to C₃₀ alkyl, C₁ to C₃₀ cycloalkyl, aromatic group and mixturesthereof; and R_(3h) represents a non-fluorinated C₁ to C₄₀ organicresidue end group.
 5. A compound of claim 4 wherein R_(1f) is derivedfrom: (i) F(CF₂)_(x)CH₂X or H(CF₂)_(x)CH₂X where x is 1 to 20; (ii)F(CF₂CF₂)_(x)CH₂CH₂X where x is 1 to 10; (iii) F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H where x is 1 to 10 and y is 1 to 20; (iv)F(CF(CF₃)CF₂O)_(x)CF(CF₃)CH₂X where x is 1 to 12; or (v) mixturesthereof wherein X is —OH, —SH, —NH₂ or —NHR′ where R″ is C₁ to C₄₀alkyl.
 6. A non-symmetric, partially fluorinated compound having amolecular structure: R_(1f)—F′—R₂—F″—R_(3h) wherein R_(1f) represents awholly or partially fluorinated C₁ to C₄₀ organic residue end groupother than a fluoroalkylether group; F′ and F″ represent functionallinkages which are either alike or different and are carboxylic esters;R₂ represents the hydrocarbon backbone selected from the groupconsisting of a C₇ to C₃₀ alkyl, C₃ to C₃₀ cycloalkyl, an aromaticgroup, and mixtures thereof; provided when R₂ is an aromatic group, thenthe fluorinated compound is difunctional, and R_(3h) represents anon-fluorinated C₁ to C₄₀ organic residue end group.
 7. A lubricant oilformulation comprising: a) a lubricant oil; and b) at least onenon-symmetric, partially fluorinated compound having a molecularstructure: R_(1f)—F′—R₂—F″—R_(3h) wherein R_(1f) represents a wholly orpartially fluorinated C₁ to C₄₀ organic residue end group; F and Frepresent functional linkages which are either alike or different andare selected from the group consisting of thioesters, sulfonic esters,ureas, thioureas, amides, phosphates, thiophosphates, imines, amines,ethers, thioethers, urethanes, thiourethanes, sulfoxides, sulfones, andmixtures thereof; R₂ represents the hydrocarbon backbone selected fromthe group consisting of a C₁ to C₃₀ alkyl, C₃ to C₃₀ cycloalkyl,aromatic group and mixtures thereof; and R_(3h) represents anon-fluorinated C₁ to C₄₀ organic residue end group.
 8. A lubricant oilformulation of claim 7 wherein R_(1f) is derived from: (i) F(CF₂)_(x)CH₂X or H(CF₂)_(x)CH₂X where x is 1 to 20; (ii)F(CF₂CF₂)_(x)CH₂CH₂X where x is 1 to 10; (iii)F(CF₂CF₂)_(x)(CH₂CH₂O)_(y)H where x is 1 to 10 and y is 1 to 20; (iv)F(CF(CF₃)CF₂O)_(x)CF(CF₃)CH₂X where x is 1 to 12; and (v) mixturesthereof wherein X is —OH, —SH, —NH₂ or —NHR′ where R′ is C₁ to C₄₀alkyl.